5. Scientific Investigations

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Introduction 

Students learn that the experimental method is a dynamic process influenced by initial observations, new evidence, unexpected results or phenomena arising from the investigation. They examine the interrelated roles of practical and secondary-sourced investigations. When conducting practical and secondary-sourced investigations, students use peer feedback to refine their investigative designs and report on their findings. Students explore the importance of accuracy, validity and reliability in relation to the investigative work of a scientist. They examine the differences between a scientific investigation and a scientific report, recognising that although the report format follows a sequential order, the investigation need not. In this module, students focus on: developing and evaluating hypotheses and questions; designing and evaluating investigations, and undertaking valid scientific investigations. Students should be provided with opportunities to engage with all Working Scientifically skills throughout the course.

Great background reading: A blueprint for scientific investigations, from the University of Berkeley. This is part of a series of pages on how science works.

Practical Investigations to Obtain Primary Data

An interesting TED-ed talk. People often credit their ideas to individual “Eureka!” moments. But Steven Johnson shows how history tells a different story. His fascinating tour takes us from the “liquid networks” of London’s coffee houses to Charles Darwin’s long, slow hunch to today’s high-velocity web.

Inquiry question 1: What initiates an investigation?

Research the factors that led scientists to investigate the following, including but not limited to:

peptic ulcers( Marshall and Warren)

Plant growth( Van Helmont)

Microwaves( Spencer)

Propose a reason for the scientists undertaking their investigations above by examining the type of data or information that they sought, for example:

  • finding relationships or patterns in identified phenomena
  • testing the conclusion of a previous investigation
  • utilising scientific knowledge and understanding to make more accurate predictions and develop new technologies
  • determine the hypotheses that were tested in each of the scientific investigations above.
  • describe where deviations from the traditional and linear models of scientific methodology were necessary in order to test each hypothesis in the investigations above.

Some useful links;

Different Types of Scientific Investigations

Inquiry Question 2: What type of methodology best suits a scientific investigation?

Using examples, evaluate the objectives and data collected in an investigation by a recognised scientist or team of scientists, including but not limited to:

Marshall and Warren and peptic ulcers

Eratosthenes and Earth’s circumference

  • An article by the Khan academy is a series related to discoveries in earth and space.It mentions the method used and the issues with the precision of measurements.
  • A quick video explaining how the calculation was made.
  • Join renowned scientist Stephen Hawking as he challenges three ordinary people to think like a genius. Can they measure the earth, the solar system and even the universe – and find our true place in the cosmos? A youtube video.( approx 54 min)
  • conducting the experiment yourself by the Scientific American. Rockhampton, in Australia, runs very close to the tropic of Capricorn and can be used for calculations for us in the Southern Hemisphere.

Doppler and the Doppler effect

Priestley’s experiments with oxygen

Evaluate the methodology of the scientific investigations above by:

  • justifying the method chosen based on the subject of the investigation and the context, for example, experimental testing, fieldwork, locating and using information sources, conducting surveys and using modelling and simulations.
  • evaluating the relevance of the investigation by considering the peer-reviewed literature in the area of study justifying the suitability of the type of data that is to be collected.

Student Investigation

Students:

  • develop a method most appropriate to test a hypothesis following observation
  • justify the type of methodology used to test the hypothesis

Links to methodologies used in scientific areas to help you orh=ganise your own investigation.

some useful links;

Methodologies can include modelling, surveys, simulations, fieldwork, primary investigation and investigating others results through secondary investigations.

Methods and techniques vary depending on the relevant scientific disciplines. Below are some links are broken up into the four main branches of science that may help you when evaluating experiments and designing your own. Sourcing peer-reviewed literature in your area of interest is also a good way to view how others did their own investigations before embarking on your own. 

Physics

Chemistry

Biology

Earth and environmental science

This is an interdisciplinary science that will rely on methods used in biology, chemistry and physics.

You will find that many disciplines cross over and may require careful consideration when designing and evaluating experiments. Reading peer-reviewed work in the area of interest will offer ideas to methodologies and analysis of data. See the working scientifically page and depth study page for further information. You may also find this tool  “Designing Your Own Lab Experiments Handout” useful when beginning to prepare for an investigation of your own.

Don’t be afraid to write to an academic who studies in the area of your interest to get some ideas about designing a valid investigation. Some will also be willing to send you free copies of their research papers as well.

Reliability and Validity

Inquiry Question 3: How is the integrity of a scientific investigation judged?

Evaluate the design of the student investigation by:

  • explaining the choice of independent, dependent and controlled variables with reference to the research question
  • explaining the sample selection and sample sizes used for gathering data
  • justifying the suitability of materials used based on their relevance to the research question, availability, cost, risk and familiarity of use
  • assessing the ethics of conducting the investigation by considering confidentiality, humane treatment and animal welfare
  • predicting an achievable timeframe to conduct the investigation
  • justifying working individually or collaboratively
  • conduct the planned investigation and collect, record and analyse primary data
  • draw a conclusion or conclusions, and suggest further investigation or research by:
    • analysing the results and interpreting the data
    • explaining the relevance of the findings of the investigation in relation to the inquiry question and hypothesis
    • justifying the methodology and any changes made to improve the data collected
    • describing potential beneficial and harmful consequences when the findings are applied to a real-world scenario
  • evaluate the validity of the investigation by determining whether the tests measured what they were intended to measure
  • evaluate the reliability of the investigation by determining:
    • the consistency of the results obtained
    • measures are taken to reduce error

See the writing for science page for more information.

Reporting

Inquiry question 4: What is the structure of an investigative report?

  • review a published and peer-reviewed scientific report to determine the conventions of writing a report on a practical investigation. This link is about how to write a scientific paper and includes information about the purpose of each section and what each section should have in it in order to meet the conventions of scientific writing.
  • use a sample of a published and peer-reviewed secondary source to identify:
    • the purpose of the report
    • measures are taken to reduce error
    • the language style used
    • the presentation and structure of the report
  • compare and contrast the structures and functions of a scientific investigation and its written report
  • prepare a report on the student investigation that was carried out

Some useful links for writing and analysing a scientific paper can be found on the writing for science page on this website.